This project will establish a multidisciplinary team to identify inappropriate sources of variation in the medical care of patients with chronic ischemic heart disease, with the goal of maximizing health outcomes while most efficiently using health resources. We will develop strategies for the appropriate referral of patients for cardiac catheterization and for revascularization with either coronary angioplasty or bypass surgery. We will examine the variations in the use of cardiac catheterization, angioplasty, and bypass surgery that result in adverse outcomes or inappropriate use of resources. Differences in the performance of these technologies in different practice settings will also be examined. The strategies that will be developed will take into account expected long term health outcomes, quality of life, health care resource utilization and costs, and patient preferences. We will demonstrate the feasibility of affecting voluntary changes in physician practice patterns by disseminating the strategies in two ways; patient- specific feedback provided directly to patients and physicians, and educational programs for regional groups of physicians. Noteworthy features of this proposal include the investigative team's wide spectrum of expertise and extensive previous experience. We will be able to synthesize an approach to the care of patients with ischemic heart disease from a wide variety of sources, including detailed clinical databases, claims databases, and from diverse perspectives, including those of the patient. Completion of this project should substantially improve the health care outcomes and resource allocation among patients with ischemic heart disease.